Lagrangian Mechanics is the reformulation of Newtonian Mechanics that utilizes the Lagrangian defined by
L=T-U
where
T= total kinetic energy of a system of particles
U= sum of the potential energy functions of a system of particles
In other branches of
physics, the Lagrangian is defined as the function
L: TQ--> R
Where Q is the configuration space, a subset of R^3N
such that the action, defined as the functional,
A(q)= int(L) dt
when it reaches stationary value at {q(t)}, will
male {q(t)} the equations of
motion.
Note, int() means the integration notation with the limits of integration being positive an negative infinity, respectively.
It is shown, using the Calculus of Variations, that the equations of
motion are in such a way that they satisfy the Lagrange's Equations of
motionD(d(L)/dv)-d(L)/dq=0
Where D is the differential operator with
respect to time, d/dx stands for partial differentiation, and v is the generalized velocity.